The high profile guests are clapped as they proceed to the top table and there are a number of traditional toasts.

In a speech prepared for the Bankers and Merchants Dinner at Mansion House tonight, Andrew Parmley will stress that a Brexit deal which ensures access to the European Union single market is "vital" for City businesses.

Mr Hammond will say that ministers are in discussion with the European Investment Bank (EIB) to ensure United Kingdom projects can access its funds during the remaining period of Britain's EU membership.

The City of London Corporation confirmed shortly afterwards that the dinner would not go ahead.

A potential announcement on the deal could be delayed due to diary commitments of both leaders, the BBC reported, as well as the horrendous Grenfell Tower fire in west London, which killed at least 12 several people on Wednesday. Many more remain missing.

May made a brief private visit to the scene, as questions were being asked about the speed at which the fire spread.

The dinner is the biggest event that takes place at the Mansion House, a 250-year-old building in the heart of the City and the official residence of the mayor during their year in office, each year.

Hammond is expected to cover the issue he had meant to discuss at the dinner at a later date.

A Treasury spokesman told the BBC Hammond would deliver his speech "in the near future".

The Queen earlier said her "thoughts and prayers" are with families.

But business leaders were hoping Mr Hammond would go further by warning explicitly of the dangers of a "hard Brexit" to growth and the economy.

Parmley cited the "paramount importance" of the United Kingdom financial services sector's voice in safeguarding job creation and growth across the United Kingdom, and urged the industry to help shape the Brexit negotiations.